Alumis Inc. (NASDAQ: ALMS) experienced a catastrophic sell-off on Tuesday, with shares plummeting 59.2% to $8.89 in morning trading after the biotech announced that its lead lupus drug candidate failed to meet the primary and secondary endpoints in a pivotal Phase 2 trial. The sharp decline wiped out approximately $1.67 billion in implied equity value, based on the company's 129.4 million shares outstanding as of August 6.
The LUMUS study, which enrolled 408 adults with systemic lupus erythematosus, randomized patients to receive one of three doses of the investigational drug envudeucitinib or a placebo over a 48-week period. The primary endpoint was the BICLA response rate at Week 48. While the highest dose of 40 mg twice daily showed a 41.0% response rate compared to 35.7% for placebo, the differences were not statistically significant, with p-values ranging from 0.3455 to 0.5018 across all active doses.
Secondary endpoints, including the SRI-4 measure, also failed to achieve statistical significance overall, despite some nominal improvements. For instance, the 20 mg once-daily dose achieved a 60.9% SRI-4 response rate versus 40.4% for placebo, but the company stated that the trial did not meet its primary or secondary endpoints overall.
Interestingly, a pre-specified subgroup analysis based on interferon gene signature (IFNGS) status revealed a stark divergence. Among patients with high IFNGS levels, which comprised about 60% of the enrolled population, the 40 mg twice-daily dose achieved a BICLA response of 52.6% versus 28.6% for placebo, a 24-point improvement. However, in the low IFNGS subgroup, the opposite trend was observed, with placebo outperforming the high dose (47.5% vs. 24.4%).
This biomarker-driven split is likely to shape the design of any future Phase 3 program. The company has indicated it will engage with regulators, including the FDA and EMA, to discuss next steps. Chief Medical Officer Jörn Drappa stated, "We plan to engage regulators to discuss Phase 3 development for envudeucitinib."
Notably, the sell-off was not driven by safety concerns. Alumis reported no new safety signals, no significant cardiovascular events, and no cases of malignancy across any treatment group. The 40 mg twice-daily regimen also demonstrated the highest suppression of the interferon pathway.
As of June 30, Alumis held $502.3 million in cash and short-term investments, which provides a runway of approximately 6 quarters based on second-quarter operating cash burn of $81.5 million. Post-move, the company's market capitalization stands at roughly $1.15 billion, representing 2.3 times its cash position, indicating the market still assigns value to its psoriasis program and other pipeline assets.
The next major catalyst for Alumis is an anticipated new drug application (NDA) for envudeucitinib in psoriasis, expected in the fourth quarter of 2026. However, the lupus setback introduces significant uncertainty, with risks including the possibility that the IFNGS-high subgroup may not replicate in a larger trial, or that regulators may demand a broader patient population or an additional Phase 2 study. Continued research spending could also increase dilution risk.
Investors have reacted swiftly, with trading volume surging to 13.97 million shares by mid-morning, compared to the stock's average. The dramatic valuation reset underscores the high-stakes nature of drug development in the autoimmune space, where a single trial failure can erase billions in market value.
